We present the results of investigations of double-layer thin-film hydrogen sensors that show high
sensitivity at low operating temperatures and improved reliability. These hydrogen sensors are manufactured
using the both ion-plasma assisted sputtering and sol-gel technique. It was established that the highest
sensitivity of the sensors occurred at 100-130°C. The hydrogen sensitivity depends on hydrogen
concentration linearly starting at 50 ppm, and reaches 10<sup>4</sup> at 5000 ppm. The response time was 1-2 s and the
recovery times were less than 10 s.
We show that compared to constant power supply, pulse heating of the sensor improves the stability of
the sensor, reduces the sensitivity to humidity, and reduces performance drift. Various possibilities of
reducing CO gas cross sensitivity are also presented.